The present invention represents a novel mode to utilize a device described in PCT/SE2003/002027, which has been published as WO 2004/056697, the entire contents of which are incorporated herein by reference. The key innovative steps in this invention are:
Methods and interfaces for the combination of electrocapture-based separations (described in PCT/SE2003/002027, WO 2004/056697) with mass spectrometry for characterization and/or identification of molecules of interest. Mass spectrometry (MS) is a powerful analytical tool for the identification and characterization of peptides, proteins, DNA, RNA, drugs, other polymers and small molecules. Even though MS can analyze samples containing more that one particular type of molecules, a separation step is usually necessary when analyzing a sample having a complex mixture of molecules. This is particularly true for samples derived from biological sources such as for example, blood, urine, saliva, cell extracts or fractions, bacteria extracts or fractions. Another important application where a separation step is necessary before MS analysis is in the identification of proteins via the enzyme digestion (e.g., trysin digestion) of a single protein (or a mixture of proteins) and the following separation and injection into the mass spectrometer. In this case peptides are separated and injected into the mass spectrometer, in which one peptide with a particular mass and charge ratio (m/z) is selected for fragmentation followed by tandem mass spectrometry (MS/MS). Utilizing MS/MS, the m/z value of the fragments are determined, thus making the determination of the amino acid sequence of the particular peptide possible, in order to identify the protein from which the peptide was derived (via database search). For all these mixtures of molecules, the separation step improves the performance of the overall analysis by mass spectrometry (higher number of molecules are characterized and/or identified with increased sensitivity).